SEOUL, Nov. 23 (Yonhap) -- President Lee Myung-bak on Tuesday instructed his senior secretaries to take measures to prevent the escalation of a west sea armed clash triggered by North Korea's abrupt artillery fire.

"(We) should carefully manage the situation to prevent the escalation of the clash," Lee was quoted as saying by his spokesman before presiding over an emergency meeting of security-related ministers at an underground bunker of the presidential office.